The rock cut ditch between the bailey,on the lhs in image,and the inner castle on the rhs. see http://www.welsh-cottages.co.uk/pembrokeshire/neverncastle.php see http://www.dyfedarchaeology.org.uk/nevern/nevern.html see http://www.neverncastle.com/ see http://www.castlewales.com/nevern.html see http://www.westerntelegraph.co.uk/news/8240613.Nevern_Castle_dig_unearths_tower_block/ see http://www.cambria.org.uk/nevern/neverndigdiary.html (lots of pics)